[1.0.0-alpha2] Drupal Core requirement

PHP Attribute discovery started from 10.2 with Block (and Action I think also): https://www.drupal.org/node/3395575 →

PHP Attribute discovery started from 10.2 with Block (and Action I think also): https://www.drupal.org/node/3395575 →

Yes, but it seems it was not working for FieldType plugins until Drupal 10.3. With Drupal 10.2, out icon field type is not showing up in the "Add field" page. But I may be wrong.

Is it relevant to also update all submodules info.yml files?

So 10.3 it is.

Yes, then 10.3.

I thought about minimum version to create new plugin types with Attribute discovery, but of course for core plugins if we want to also use Attributes, then 10.3.